Relay



Sept. 13, 1938. o. T. MGILVAINE RELAY Filed Ocfi. 28, 1955 Q O 6 6 5 7 airieziij, 2,6 mm air impmmrz aprp v v in fiaan waaaafid na K 4 E4 Patented Sept. 13, 1938 UNITED STATES PATENT oFFicrS RELAY Oran T. Mcllvaine, St. Charles, 111., assignor to Mcllvaine Patent Corporation, St. Charles, 111., a corporation of Delaware Application mm 28,- 1935, Serial No. 41,043

among its objects and advantages 8. high degree of ruggedness and resistance to injury by mechanical shock, and a minimum requirement of actuating energy in proportion to the energy characteristics of the controlled circuit.

- In the accompanying drawing:

Figure 1 is a vertical section of a device according to the invention; and

Figure 2 isan enlarged section on line 22 of Figure 1.

In the embodiment of the invention selected for illustration the movable parts are housed in a glass shell comprising a cylindrical tube l0 necked in as at l2 to form an inner supporting shoulder and then flared outwardly as at l4 to form an outward supporting shoulder. This much of the shell is defined by surfaces of revolution except for the sealing tip 15 at the top. Below the flange H the walls are brought in to define a flat bridge chamber "5 and two substantially cylindrical wells i8 and 20 separated by the spacing arch 22.

Lead wires 24 and 26 are sealed into the bottoms of the-we11s 20 and I8 and immersed in the mercury filling 28. The circuit closing element is in the form of a bridge having a bight 30 at the top and spaced downwardly extending legs 32 and 34. In small units the entire bridge is of tungsten, but it will be obvious that in larger constructions most of, the bridge could be made of cheaper conducting material with tungsten tips at the bottoms of the legs. The bridge is supported and actuated by a plunger built up of an upper portion 35 oi. magnetic material such as iron, and a lower portion 38 of non-magnetic material such as brass. I have illustrated the portion 38 as tubular and united with the portion 36 by slipping it. over a tip 40 of reduceddiameter, after which the metal of the tube 38 may be spun into the groove 42 at the base oi the tip 40. The all tungsten bridge illustrated is welded to a shank '44 provided with a similar tip 46 entering the bottom of the tube 38.-

The plunger and tube are normally supported in the position illustrated by a compression spring 48. Near the upper end of the magnetic portion 36 Iiorm an annular groove Ill and the upper end turns of the spring 48 are of gently decreasing diameter down to a diameter slightly smaller than that of the groove 50. Thus the plunger can be thrust inside the spring and the end turn will be resiliently expanded to slide down over the plunger portion 36 until it comes to the groove 5|] and snaps into place.

The lower end of the spring 48 is supported by the abutment I2. I prefer to provide an annular washer 5i shaped to lie against the abutment l2 and of sufilcient vertical dimensions to avoid danger of tipping, which washer afiords a flat seat for the lower end of the spring 48.

The solenoid 52 rests on the flange l4, and its upper end is adjacent the lower end of the magnetic portion 36 of the plunger. Depending on the operating characteristics desired, 1 may make the stud 44 of magnetic or o! non-magnetic material, and I may make the washer ii of magnetic material such as iron, or of ceramic or other non-magnetic material.

The lead wires 54 and 56 for the controlling circuit have been illustrated as covered with insulation at 58. These lead wires pass out through the top cover lillof the cylindrical sheet metal casing 62, being guided through suitable apertures by means of the insulating bushings 64. Similarly, the lead wires 24 and 26 pass out through the bottom cover 66. These lead wires have been illustrated as being of the'same outside diameter as the diameter of the insulation 58. Accordingly, they ,are guided out by insulating bushings 64 identical with those at the top.

The space between the glass shell and the sheet metal casing 62 may be occupied by gas, liquid, or solid, but for ordinary commercial uses excellent mechanical protection as well as insulating properties may be secured by pouring in a filling of molten tarry insulating material which completely fills the casing 62 and congeals in placmso as to aflord both a mechanical support for holding the shell and solenoid in place and a material mechanical cushioning action against blows received by the shell 62. It will be noted that by varying the characteristics 01 the spring 48 different time characteristics canbe given to the movement of the bridge. When the bridge moves up, two vertical arcs are drawn from the. mercury 28, and the magnetic field of the current tends to move these arcs away from each other and thus assist in their extinguishment. When the filling 2B is of mercury, I prefer to fill the shell before sealing, with hydrogen. The use of a hydrogen filling material in excess of atmospheric pressure greatly increases the resistance to the flow of current in an are within the shell.

Devices according to the invention may be designed ior an extremely-wide range of current varying capacities. At all capacities I find it possible to employ an unusually small amount of energy in the solenoid 52 compared with the energy characteristics of the controlled circuit. It will be obvious that the embodiment disclosed is primarily suitable for controlled circuits that are open most of the time. However, for controlling circuits that are normally closed, it will be obvipus that the plunger portions 36 and 38 could be interchanged and the solenoid 52 moved up to the top of the sleeve ill, with the spring 48 enencircling said plunger and normally holding said plunger and bridge elevated and the relay open; said plunger being built up of an upper portion of magnetic material and a lower portion of nonmagnetic material; an annular solenoid winding adjacent said non-magnetic plunger portion for attracting the magnetic plunger portion to move into the position normally occupied by the nonmagnetic plunger portion and close said relay; a hermetically sealed non-conducting enclosing shell comprising a tubular portion telescoped in said solenoid and housing .said, plunger and spring, a spring abutment shoulder near the bottom of said tubular portion, an outwardly extending flange underlying said solenoid, a bridged chamber below said flange, and spaced wells at the bottom of said chamber for receiving said legs; said chamber being flattened to guide said legs into said wells; lead conductors for the controlled circuit entering the bottoms of said wells; lead conductors for the controlling circuit extending up from said solenoid; a sheet metal casing enclosing said shell and spaced therefrom throughout; insulating bushings for said leads in the top and bottom of said casing; a filling of mercury in said wells; a filling of hydrogen at more than atmospheric pressure occupying the rest of the'space inside said shell; and a filling of solid insulating material congealed inside said casing and aflording mechanical support and protection to said shell; said shell being shaped throughout so that the mercury filling for the wells can drain back into the wells from any portion of the shell.

2. In a relay, in combination: a vertical bridge having its bight uppermost and its legs projecting downward; an actuating plunger extending vertically upward from said bridge and integrally united therewith; a helical compression spring encircling said plunger and normally holding saidplunger and bridge elevated and the relay open; said plunger being built up of an upper portion of magnetic material and a lower portion of nonmagnetic material; an annular solenoid winding adjacent said non-magnetic plunger portion, for attracting the magnetic plunger portion to move into the position normally occupied by the nonmagnetic plunger portion and close said relay; a hermetically sealed non-conducting enclosing shell comprising a tubular portion telescoped in said solenoid arid housing said plunger and spring, a spring abutment shoulder near the bottom of said tubular portion, an outwardly extending flange underlying saidsolenold, a bridged chamber below said flange, and spaced wells at the bottom of said chamber for receiving said legs; said chamber being flattened to guide said legs into said wells; lead conductors for the controlled circuit entering the bottoms of said wells; lead conductors for the controlling circuit extending out from said solenoid; a filling of mercury in said wells; and a filling of hydrogen occupying the rest of the space inside said shell.

3. In a relay, in combination: a vertical bridge having its bight uppermost and its legs projecting downward; an actuating plunger extending vertically upward from said bridge and integrally united therewith; a helical compression spring encircling said plunger and normally holding said plunger and bridge elevated and the relay open; said plunger being built up of an upper portion of magnetic material and a lower por tion of non-magnetic material; an annular solenoid winding adjacent said non-magnetic plunger portion, for attracting the magnetic plunger portion to move into the position normally occupied by the non-magnetic plunger portion and close said relay; a hermetically sealed non-com ducting enclosing shell comprising a tubular portion telescoped in said solenoid and housing said plunger and spring, a spring abutment shoulder near the bottom of said tubular portion. an outwardly extending flange underlying said solenoid, a bridged chamber below said flange, and

spaced wells at the bottom of said chamber [or receiving said legs; said chamber being flattened to guide said legs into said wells; lead conductors for the controlled circuit entering the bottoms of said wells; lead conductors for the controlling circuit extending out from. said solenoid; and a filling of conducting liquid in said wells.

4. In a relay, in combination: a vertical bridge having its bight uppermost and its legs projecting downward; an actuating plunger extending vertically upward from said bridge and integrally united therewith; a helical compression spring encircling said plunger and normally holding said plunger and bridge elevated and the relay open; said plunger being built up of an upper portion of magnetic material and a lower portion of non-magnetic material; an annular solenoid winding adjacent said non-magnetic plunger portion for attracting the magnetic plunger portion to move into the position normally occupied by the non-magnetic plunger portion and close said relay; a hermetically sealed non-conducting enclosing shell comprising a tubular portion telescoped in said solenoid and housing said plunger and spring, a spring abutment shoulder near the bottom of said tubular portion, an outwardly extending flange underlying said solenoid, a bridged chamber below said flange, and spaced wells at the bottom of said chamber for receiving said legs; said chamber being flattened to guide said legs into said wells; and contacts in said wells to engage said legs when said bridge is lowered by said solenoid.

ORAN T. MCILVAINE.

v w CERTIFICATE OF CORRECTIONO Patent No. 2,129,855,, September 1 19 8. A ORAN 1 McILVAINT' It is hereby certifiefi that error appears in the printed specfiication of the above vmnnberecipatnt requiring correction as follows: Page 1 second column, line 55, for the word varying rea carrying; ahd that the said Letters Patent shouldbe read/with this corrqctionthe'rein that thesam may conform to the record of the cage. in. the Pateht Ofiflto Signed and sealed this 15th day of November, A. D. 19 8 Henry Vart Arsdala (Sqal) I Actjng Commissioner of Patents.

CERTIFICATE OF CORREC'IIOII o Patent No. 2,129,855; September 15, 1938. ORAN 1'; McILvAIm It is hereby certified {that errorepp'ears in the printed spec ificati on of the above numbered patent requiring cornegtion es follows: Page 1 second column, line 55, for the word "varying" read carrying and that the said Letters Patent should be readwith this cori'ectiontherein that the'same; may conform to the record of the cese. in the Patent Ofiio e,

Signed and sealed this 15% day of November A. b.1958,

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

